Abstract:
In the present study, some histochemical features of goblet cells of the intestine of convict cichlid (A. nigrofasciata) were described. In order to reveal the main histological construction, transverse sections of different parts of intestine were firstly stained with hematoxylin eosin (H-E). Sections of anterior, mid and posterior intestinal segments were also treated with different staining methods of alcian blue (AB) at pH 2.5, aldehyde fuchsin (AF), periodic acid-Schiff (PAS), KOH/PAS and PAS/AB (pH 2.5) and investigated. Goblet cells of anterior intestine were colored strongly by AB (pH 2.5), AF and PAS; and moderately by PAS/AB (pH 2.5) (AB dominant). In the mid part of the gastrointestinal tract, goblet cells were also stained strongly with AB, PAS and PAS/AB (pH 2.5) (AB dominant), however, their reactions to KOH/PAS treatment were recorded as negative. Because of numerous supranuclear vacuoles of the epithelial cells, only a few goblet cells could be differentiated in posterior parts of alimentary channel, with their weakly reaction to AB (pH 2.5), PAS and PAS/AB (pH 2.5). Moreover, these cells were not stained with AF and KOH/PAS. According to their affinities, goblet cells oriented in anterior and the mid intestine were mainly classified as acidic (AB-positive) and neutral (PAS-positive). Statistical analysis were confirmed that, the numbers of acidic and neutral cells of per unite square of epithelial area were significantly different.
